Preconcentration and separation of inorganic selenium on Dowex 1X8 prior to hydride generation—atomic absorption spectrometry

Abstract

Exchange reactions between inorganic selenium species and chloride were studied on Dowex 1X8. The concentration exchange constants were determined with the batch technique at room temperature and used to predict the chromatographic enrichment and separation of tetra- and hexavalent selenium. A procedure for the determination of total selenium after digestion with permanganate and anion exchange preconcentration was also developed. The enrichment techniques were applied to the determination of Se(IV) and total dissolved selenium in drinking water and fresh water using flow injection hydride generation—atomic absorption spectrometry (HG—AAS). Results agreed with those obtained in a HG—AAS system where selenium was preconcentrated as hydrogen selenide in a trap at liquid nitrogen temperature.